Muammar Gaddafi speaks at the UN general assembly in New York. Photograph: Jason Szenes/EPA

Muammar Gaddafi threw the UN general assembly into chaos today when he effectively hijacked the podium to make a rambling, unscripted speech.

The Libyan leader had been scheduled to speak for 15 minutes but spoke for over an hour and a half, in a wide-ranging, passionate address which took in the UN security council, the assassination of US president John F Kennedy, Somali piracy and a theory that swine flu was created for military purposes.

Gaddafi took to the rostrum at 4pm, prompting several UN delegates to leave the hall. When they tentatively returned 30 minutes later, expecting the Libyan to have finished, he was only a third of the way into his speech.

Gaddafi, who frequently broke off to pore over pages of notes, said the security council should be called "the terror council", saying: "We cannot have the security council under countries which have nuclear powers. This is terrorism itself."

The Libyan leader, who arrived in New York yesterday, also called for a permanent seat on the security council for the African Union - prompting applause from a handful of African states - and invited anyone who disagreed with him to an impromptu debate on the general assembly floor.

An hour into his speech, Gaddafi complained at some length about being jet-lagged from the 10-hour flight to New York, and having to get up early for the general assembly. Dressed in long brown robes and wearing a black hat, Libya's leader gesticulated with his speech papers - revealing his notes to be handwritten, at a variety of angles and in various colours, on pieces of paper torn from a notebook.

He eventually left the floor at 5.33pm, having promoted his website, Gaddafi Speaks.

Gordon Brown had been due to speak at the end of the morning session, but it is not clear if that will still happen.

Despite the mind-numbing length of his speech Gaddafi failed to break the all time record set by Cuban leader Fidel Castro in 1960, at four and a half hours.